How to test & replace a leaf blower’s fuel primer bulb

A faulty primer bulb doesn’t just make starting your leaf blower harder; it can also lead to stalling or uneven performance. The good news? Testing and replacing a primer bulb is a simple fix you can handle yourself. We’ll walk you through how to test it and how to replace it if necessary, so you can get your blower back in action and your yard looking great.

If you find out that you need any replacement parts for your appliance while you’re troubleshooting, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

What is the primer bulb?

The primer bulb is a small but essential part of your leaf blower’s fuel system. Its job is simple: it manually pumps fuel from the tank into the carburetor, ensuring there’s enough fuel for the engine to start smoothly. Without it, starting your blower would be a lot harder, especially if it hasn’t been used for a while.

Over time, primer bulbs can wear out due to exposure to fuel, frequent use, and changing weather conditions. Cracks, stiffness, or failure to fill with fuel are all signs that the primer bulb may be the problem. Sometimes, blockages in the fuel lines can also prevent the primer bulb from working correctly.

Read more: How to fix a leaf blower that starts and then stalls

Safety precautions

When working on any appliance, remember to keep safety first. Here are some tips to keep in mind:

• Before performing any maintenance or repair tasks, disconnect the spark plug wire to prevent accidental starting of the engine.
• If working indoors, make sure there is adequate ventilation to prevent the buildup of exhaust fumes. Carbon monoxide poisoning can be a serious risk.
• Wear insulated work gloves to protect your hands from sharp metal parts, pinching hazards and debris.
• Never attempt to service or repair while it is running or when the engine is still warm. Wait for all moving parts to come to a complete stop.
• Exercise extreme caution when working near blades, augers, or any other moving parts. Keep your hands, fingers, and clothing clear of these areas at all times.
• If the appliance has recently been used, give it plenty of time for any hot parts to cool down before working on it.
• Empty the gas tank before beginning any work. Refill using fresh fuel.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Take your time and don’t rush while working to prevent accidents and personal injuries.
• Work in a well-lit area so you can clearly see and access the interior parts.
• Clear your workspace of clutter and other obstacles. Keep children and pets away from the work area.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause injury.
• Wear safety glasses when working with chemicals, dust or cleaning large debris to prevent injury.
• Follow the manufacturer’s recommended maintenance schedule including checking fluid levels, inspecting belts and cables, and cleaning or replacing filters.
• When not in use, store the machine in a safe and dry location.

Note: The information provided in this article may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

Read more: Troubleshooting and Fixing a Leaf Blower that Won’t Start

Tools and materials needed

Tools

• Screwdrivers: both flathead and Phillips, depending on the screws securing your primer bulb.
• Needle-nose pliers: for removing and reattaching fuel lines.

Materials

• Replacement primer bulb: make sure it’s compatible with your leaf blower model.
• Rags or paper towels: for cleaning up small fuel spills or wiping components.

Safety gear

• Gloves: protect your hands from fuel and small parts.
• Safety goggles: guard your eyes against fuel splashes or debris.
• Well-ventilated workspace: work in an open area to avoid inhaling fuel fumes.

Read more: The Ultimate Guide to Leaf-Blowing

Test the primer bulb

Testing your primer bulb is the first step to determining whether it needs to be replaced or if the problem lies elsewhere in your leaf blower’s fuel system.

Step 1: Prepare the blower

1. Turn off the leaf blower and allow it to cool completely.
2. Disconnect the spark plug wire to ensure safety during the repair.
3. Drain the fuel tank to prevent spills while working.

Step 2: Locate and remove the faulty primer bulb

1. Locate the primer bulb assembly, typically near the carburetor or fuel tank.
2. Use a screwdriver to remove any screws securing the bulb’s housing. Keep the screws in a safe place for reassembly.
3. Gently pull the primer bulb out of its housing.
4. Disconnect the fuel lines attached to the bulb using needle-nose pliers. Note which line connects where for accurate reassembly.

Step 3: Visual inspection

1. Examine the primer bulb for any visible damage. Look for cracks, punctures, or signs of wear, such as stiffness or discoloration.
2. Press the bulb lightly. If it feels brittle, doesn’t spring back, or doesn’t move at all, it’s likely faulty.

Step 4: Functional test

1. Press the primer bulb and observe what happens.
2. If the bulb stays flat or doesn’t fill with fuel, it’s not functioning properly.

Step 5: Check for blockages

1. Inspect the fuel lines connected to the primer bulb. Blockages or cracks in the lines can prevent proper fuel flow.
2. Disconnect the lines from the primer bulb using needle-nose pliers and check for obstructions or damage.

If the primer bulb looks fine and fuel flows properly through the lines, the problem might be with the carburetor or another part of the fuel system.

If your tests reveal that the primer bulb is damaged or not functioning, it’s time to replace it. The next section will guide you through the replacement process.

Replace the primer bulb

Step 1: Install the new primer bulb

1. Attach the fuel lines to the corresponding ports on the new primer bulb. Ensure a secure connection to prevent leaks.
2. Place the new bulb into the housing, aligning it correctly.
3. Secure the housing with the screws you removed earlier, tightening them evenly.

Step 2: Test the new primer bulb

1. Refill the fuel tank with fresh fuel.
2. Reconnect the spark plug wire.
3. Press the new primer bulb several times to check for proper function.
4. Start the blower and let it run for a few minutes.

Additional information

Thanks for reading! If you need replacement parts, grab your model number and head to AppliancePartsPros.com. We offer over two million parts and most orders arrive in two business days. If you need help finding the right part or placing an order, you can contact our team at 1 (877) 477-7278.

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